All good stuff. I think the best option IMHO is a drop-in replacement for AppEngine. This way a service can start easily on AppEngine and when it's big enough,

All good stuff. I think the best option IMHO is a drop-in replacement for AppEngine. This way a service can start easily on AppEngine and when it's big enough, can roll out on its own infrastructure. Interestingly... this is the same play MS used to gain prominence: they controlled the API and the more code was written for it, the network effects kicked in with more force. Very interesting parallels here.